Method of rustproofing iron and steel reinforcing elements for steam cured concrete



Parts When preparing the coating.compositions according to the above mentioned examples, the lime vand the siliceous materials andthe bulk of the water are preferably,iirstfmixedV together,

and the binding agent is then added dissolved in the remaining Water. In case of using the preferred binding material, casein, the caseinv may suitably be dissolved in water in the presnco'f `a"s"1.llfduantityof 'tl'iev lime which facili-'- tatsjthef-dis'solution. if al'chromate' is used, kthis' is preferably adiedtothesoluton ofthe bindingiinaterialfbefore 'the `addition off the.' latter tothe sluriy'of lime andfsiliceousmaterials i "','lhe"1applieation 'of the slurry Y coating on ythe reinforcing? elements mayzbe effectediin any suitable manne'rgl'ior example'by dipping, brushing, spraying 'orf"other"lrnethodaA The drying of the c'oa'tingis` suitably accelerated kby the application of v"heated air,y for:4 example: by. exposing the coated- 4elements4 to f'a current f of air heated y.to aMtmperatureof 30 idr asuiiicienttime.v

- -The`coated reinforcing elements thus'obtained are embedded-Ti; in' concrete,"f preferably i lightweight' concrete,`4 which is: -subjected `to a Hsteam.- curing in autoclaves, as known per yse; preferablyfat anfov'er'pressure oid-12- -kgs.,1 and hereby the reactions' taire place iby-Jmeans of Which the coating is converted to a'tight water-proof bond betw'eenf the reinforcing`"elem`ents and theV concrete@ 53-0" ,1 'i 1 ln: i'

'*Altlio'ugh the f invention* above has been described with reference tolreinforcing elements ofironfand steeLrour coatings yare alsofsuitable forfthe treatment' ofl lother" types offv metal reinforcing-elements'liableito rusting.-

invention have beenihereinabove indicated, it will bev understood'that theinventionmofzthis application is not limited to the specific exampleslherein recited but that numerous modiiications-and Variations thereof may be made without departing from the principles o'f-l-ou'r iinvention.`

. f 4.We claim:

* Thi-.method of rust-proonng noname steel reinforcing, .elements *for steam-cured concrete, which comprises coating such elements with a V3. The process of claim 1 wherein the hydrophilic organic colloidal binding material is added tothe composition ina quantity of about 2-20%,

lcalculated on the weight of the mixture of lime and siliceous material.

4, The process of claim 1 wherein the hydro- ,vphilic organic colloidal binding material is a l proteineous substance.

5. The process of claim 1 wherein the hydrophilic organic colloidal binding material is carbohydrate.. c

6. The proces'sfof claim 1 wherein the hydrophilic organic colloidal binding material is a. water-soluble cellulose derivative.

. ''..The process of claim 1 wherein the hydrophilic organic colloidal binding material is casein. f8. The processof claim l wherein the coating composition contains a small amount fof a'dissolved alkali metal'chromate as a rust-proofing agent.,` Y, o, ff .l

9. The process of claim ljwher'ein the coating applied on the reinforcing elementslis driedmy the application of heated air.4 I l l0. The process of claim l `whereintheconcrete is a light-weight concrete, if

1l. In the making of reinforced'fsteam-cured concrete wherein rust-prooied ironand steel reinfcrcing elements are employe d`, 'V the process y which comprises, coating' the reinforcing elements with an aqueous slurry of 'aiinely ground mixture containing about 60-2Gv%1by vveight'ofl limel and z1z0-80570 by weight of a' reactive siliceous material and a smallproportion ofcaseinsuicient to renl der, the coating Atough o and to produce a binding to arcuring by steam, wherebyA thelime and siliceous components ofthe coating react. with each other and setV producing `a tight waterproofvjoint betweenthe reinforcing elements and the concrete.

2. The process of claim 1 wherein the mixture'of lime and siliceous material in ,the coataction in the coating, drying thejcoating thus applied beio're it'ha's had timeto set,`.embedding the so-coated reinforcing elements in a concrete grout"and4 subjecting thewhole lto acuring by steam,`whereby inthe steam-curing operationthe lime'reacts with the siliceous material producing cured water-tight joints between the reinforcing elements and the concrete. l

"i 12. '1n vthe makingfof reinforced steam-cured concrete wherein'rust-proofed iron andsteelreinforcingelements are employed, the process which Acomprises coating the reinforcing elements -with anaqueous slurry of a nnely ground mixture containing about 60-20 by weight of lime, cioby' weightcf ra A reactive siliceous` material and about 2-20%jof casein, calculated on the weight of the mixture of limej'a'nd siliceousmaterial-,and suii'icient l sodium''chromate to actv as a rustinhibitor,V drying'the coating thus applied, embedd'ing'the so-ooated reinforcing elements in'a concrete groutl and subjecting the whole to a curing by `steam,"whereby`in the steam-curing operation the lime'reacts with the siliceous material producing cured water-tightioints between the reinforcingelements and the concrete.- i

' 'LENNART HANS SIMONSSON. l

' LEO TORSTEN UILFS'IJ'EDT.4

i REFERENCES CITED The following references are of record in the iillefof this patent: f Y

UNITED STATESPA'IENTS 

1. THE METHOD OF RUST-PROOFING IRON AND STEEL REINFORCING ELEMENTS FOR STEAM-CURED CONCRETE, WHICH COMPRISES FOR STEAM-CURED CONCRETE, LIQUID AQUEOUS SLURRY OF A FINELY GROUND MIXTURE OF LIME AND A REACTIVE SILICEOUS MATERIAL CONTAINING A SMALL PROPORTION OF A HYDROPHILIC ORGANIC COLLOIDAL BINDING MATERIAL WHICH AT LEAST SWELLS IN WATER IN AN AMOUNT SUFFICIENT TO RENDER THE COATING FLEXIBLE AND TOUGH AND TO PRODUCE A BINDING ACTION IN THE COATING, DRYING THE COATING THUS APPLIED BEFORE IT HAS HAD TIME TO SET, SURROUNDING THE SO-COATED REINFORCING ELEMENTS WITH A CONCRETE GROUT, AND SUBJECTING THE WHOLE TO A CURING BY STEAM, WHEREBY THE LIME AND SILICEOUS COMPONENTS OF THE COATING REACT WITH EACH OTHER AND SET PRODUCING A TIGHT WATERPROOF JOINT BETWEEN THE REINFORCING ELEMENTS AND THE CONCRETE. 